I brewed these up today, super quick, so they're probably not the best, but I'd love to hear some feedback on each of them. The first one is an idea that I had when Perfect Cell (Docent of Perfection) was spoiled, but I also recognize that you could probably take out the enchantment and toss in more tempo/removal.
As for the second one, oh god is it funny to play at the very least. If you can manage to untap with 4 of the "target creature" spells in hand and 4 mana, you can get an insane amount of damage going at your opponent, but then that is just "win more"
I think the problem you run into with both, and particularly the RG deck, is that it has a lot of weak cards if you don't draw your combo pieces (Zada/Silverfur) or if they get removed. So you lose some games simply to variance in addition to the usual bad luck draws. Some way to tutor for Zada like Eldritch Evolution might help. The UR deck is better because it has multiple engines, cards like Anticipate to draw into the pieces it needs, and more interaction with the opponent to stall them until you get your plan together. My main concern with the UR deck is that 4x of Docent and Nibilis may put your curve too high and too much at sorcery speed for those mid game plays, particularly when both die to Languish. Bedlam Reveler looks very interesting for this kind of deck, and I've actually had some good experiences with Guardian of Tazeem, which hits that nice 5 toughness threshold and does similar work to the Nibilis.